managing streams in dart

[poborin]

I'm trying to decide the best way to integrate a library, and I have two options:

1. Subscribe to a Rust stream directly within a widget and then unsubscribe when the widget is removed.
2. Create a global class to manage all Rust stream subscriptions and handle event dispatching throughout the app.

At the moment, it seems like I can only go with option 2 because there isn't a function available to unsubscribe from the stream.

[temeddix]

Hi :)

Could you elaborate a little about what youre trying to do? Are you trying to handle every single signal from Rust, or just show something from the received signal on the screen?

If latter, I would recommend using StreamBuilder widget in Flutter. I think it's closer to the first option you provided, but without further details I think this is the best I can get.

[poborin]

Let's say I have a multipage app with three screens: Home, Page 1, and Page 2. From the Home screen, I can navigate to either Page 1 or Page 2 and then return to Home. Both Page 1 and Page 2 require a state that is managed by Rust to fetch some data from the backend. I hope it makes sense. Additionally, this app is being targeted for iOS, Android, and WASM platforms.

How would you organise a subscription to Rust streams in this case? I'm very new to Flutter and not 100% sure how the Navigation works: would it dispose a subscription to a rust stream when you navigate back, so the page does not hang in the navigation stack?

[temeddix]

In this case, I would use NavigationBar widget and simply put StreamBuilder that listens to Rust messages inside each page. Since each page widget is stored in a list field of NavigationBar, each page will be not be disposed on tab switch; they will always maintain the latest state received from Rust.

[temeddix]

There are some tab widgets in Flutter that doesn't dispose the page widget on switch, but only hides it while keeping it in a list